Domestic "matsutake" mushrooms, usually a high-priced fall delicacy in Japan, have become more affordable due to a good harvest, with wholesale prices halving in some areas.

Transaction volumes for Japan-grown matsutake rose 40 percent from a year earlier and they have been selling well due to lower prices, traders said.

On the other hand, prices of imported matsutake, which are a cheaper alternative and mostly come from China, have been rising, with their transaction volume declining.

For a good matsutake harvest, a moderate amount of rainfall is necessary through September, when temperatures go down.

In Nagano Prefecture, known as a major mushroom producer in central Japan, rainfall and ground temperatures were both favorable for the growth of matsutake this year, according to the prefecture's forestry industry center.

The total amount of domestic matsutake mushrooms traded at the Tokyo Metropolitan Central Wholesale Market in August and September reached 4.0 tons, up around 1.2 tons from a year earlier.

The average wholesale price per kilogram fell around 30 percent, and that of matsutake from Nagano halved from a year before to around 25,000 yen ($220).

Matsutake from another major producer, Iwate Prefecture in northeastern Japan, saw about a 20 percent fall in the average wholesale price to some 47,000 yen.

"Some domestically produced matsutake fetched 100,000 yen per 400 grams in the previous year because of scarce quantities. But the highest price this year was about 70,000 yen," said an intermediate wholesaler at the Ota Market in Tokyo.

At the Daimaru department store in Tokyo, the price of matsutake was down 10 to 20 percent from the previous year and sales have been strong, according to the retailer.

The situation is the same at stores of major retailer Aeon Co., a company official said of the mushrooms, which are now in late season.

At Japanese restaurant Ginza Wakuta in Tokyo's posh Ginza district, fall delicacy dishes using both domestic and imported matsutake are served.

"This year, many domestic matsutake were available by mid-October and their prices were reasonable as well," the owner of the restaurant said.

In contrast, matsutake imports have been on a declining trend in recent years, halving from 2009 to 2017 along with the falling consumption of the mushrooms, which are considered a little pricey by many shoppers.

Chinese matsutake prices rose about 10 percent to some 7,900 yen per kg at one point, with trading volume falling 20 percent from a year earlier, according to one of the traders.